1] H. Abdollahzadeh Ahangar, M.A. Henning, C. Löwenstein, Y. Zhao, and V. Samodivkin, Signed Roman domination in graphs, J. Comb. Optim. 27 (2014), no. 2, 241–255.
[2] M. Chellali, N. Jafari Rad, S.M. Sheikholeslami, and L. Volkmann, The Roman domatic problem in graphs and digraphs: A survey, Discuss. Math. Graph Theory, (to appear).
[3] E.J. Cockayne and S.T. Hedetniemi, Towards a theory of domination in graphs, Networks 7 (1977), no. 3, 247–261.
[4] T.W. Haynes, S.T. Hedetniemi, and P.J. Slater, Fundamentals of Domination in Graphs, Marcel Dekker, Inc., New York, 1998.
[5] M.A. Henning and L. Volkmann, Signed Roman k-domination in graphs, Graphs Combin. 32 (2016), no. 1, 175–190.
[6] E.A. Nordhaus and J.W. Gaddum, On complementary graphs, Amer. Math. Monthly 63 (1956), no. 3, 175–177.
[7] S.M. Sheikholeslami and L. Volkmann, The signed Roman domatic number of a graph, Ann. Math. Inform. 40 (2012), 105–112.
[8] S.M. Sheikholeslami and L. Volkmann, Signed Roman domination in digraphs, J. Comb. Optim. 30 (2015), no. 3, 456–467.
[9] P.J. Slater and E.L. Trees, Multi-fractional domination, J. Combin. Math. Combin. Comput. 40 (2002), 171–181.
[10] L. Volkmann, The signed Roman k-domatic number of a graph, Discrete Appl. Math. 180 (2015), 150–157.
[11] L. Volkman, Weak signed Roman domination in graphs, Commun. Comb. Optim. 5 (2020), no. 2, 111–123.
[12] L. Volkman, Weak signed Roman k-domination in graphs, Commun. Comb. Optim. 6 (2021), no. 1, 1–15.